<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>小白教程(css5.net)</title>
<script>
function changeTarget(){
document.getElementById(’runoob’).target="_blank";
}
</script>
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<body>
<a id="runoob" href="//www.css5.net">访问小白教程</a>
<br><br>
<input type="button" onclick="changeTarget()" value="修改target">
<p>尝试在你单击按钮之前点击链接。</p>
</body>
</html>